The fresh plant in India is commonly eaten as a green vegetable, while the seeds are extensively used by the natives in food and medicine.
TRAGACANTHA.
Gummi Tragacantha; Tragacanth, Gum Tragacanth; F. Gomme Adragante; G. Traganth.
Botanical Origin.—Tragacanth is the gummy exudation from the stem of several pieces of Astragalus, belonging to the subgenus Tragacantha. The plants of this group are low perennial shrubs, remarkable for their leaves having a strong, persistent, spiny petiole. As the leaves and shoots are very numerous and regular, many of the species have the singular aspect of thorny hemispherical cushions, lying close on the ground; while others, which are those furnishing the gum, grow erect with a naked woody stem, and somewhat resemble furze bushes.
A few species occur in South-western Europe, others are found in Greece and Turkey; but the largest number are inhabitants of the mountainous regions of Asia Minor, Syria, Armenia, Kurdistan and Persia. The tragacanth of commerce is produced in the last named countries, and chiefly, though not exclusively, by the following species[704]:—
1. Astragalus adscendens Boiss. et Hausskr., a shrub attaining 4 feet in height, native, of the mountains of South-western Persia at an altitude of 9,000 to 10,000 feet. According to Haussknecht, it affords an abundance of gum.
2. A. leioclados Boiss.
3. A. brachycalyx Fisch., a shrub of 3 feet high, growing on the mountains of Persian Kurdistan, likewise affords tragacanth.
4. A. gummifer Labill., a small shrub of wide distribution occurring on the Lebanon and Mount Hermon in Syria, the Beryt Dagh in Cataonia, the Arjish Dagh (Mount Argæus) near Kaisariyeh in Central Asia Minor, and in Armenia and Northern Kurdistan.
5. A. microcephalus Willd., like the preceding a widely distributed species, extending from the south-west of Asia Minor to the north-east coast, and to Turkish and Russian Armenia. A specimen of this plant with incisions in the stem, was sent some years ago to the Pharmaceutical Society by Mr. Maltass of Smyrna. We received a large example of the same species, the stem of which is marked by old incisions, from the Rev. W. A. Farnsworth of Kaisariyeh, who states that tragacanth is collected from it on Mount Argæus.